Motor vehicles are known in the prior art that comprise a body in white made up in its bottom portion of longitudinal structural elements and transverse structural elements. These elements are more particularly closed metal section members and they extend respectively in the longitudinal direction of the vehicle or in its transverse direction. The longitudinal structural elements may extend between the front and rear axles of the vehicle, in which case they are referred to as “underbodies” in this application (even though they are also referred to as “side rails” by other specialists in the field). They may also be situated in front of or behind these axles, in which case they are referred to as “side rails” in this application (even though they are also referred to as “longitudinal members” by other specialists in the field). The transverse structural elements are referred to as “cross-members” in this application.
More particularly a motor vehicle is known, in particular from patent FR 2 890 366, that comprises a floor made up of two superposed portions, the floor incorporating a vehicle electric battery arranged between the two portions of the floor. The floor is put into place in such a manner as to be connected to the longitudinal and transverse structural elements of the body in white of the vehicle.
Such a floor is appropriate for vehicles that possess a battery of relatively small capacity, e.g. for hybrid vehicles that include both an engine and an electric motor for providing propulsion. Nevertheless, when the capacity of the battery increases, thereby increasing its volume, the prior art architecture requires the cross-members of the vehicle to be raised and the structural elements to be redimensioned, or even additional structural elements to be provided, in order to reinforce the bottom portion of the body and prevent the battery from being damaged in the event of an impact involving the vehicle.
Such a vehicle architecture is also disadvantageous in that it increases the weight of the vehicle, while reducing the space available inside the vehicle cabin.